5 replies to this topic

[Meysam_45000]

Dear Friends,

 

I am writing to ask a question about cooling water system for cooling the casing and packing of reciprocating hydrogen compressors. This cooling system has two centrifugal pumps, two heat exchangers and one reservoir. In manual of this compressor we have a sheet about this system which explains about the quantity of filling fluid (mix of Glycol and  DM Water). I have measured the dimension of reservoir of this system and the volume of just this part is about 900 liters (up to 100% nut on level gauge from bottom), but in manual the filling amount for all of these parts is 600 liters. Now I am confused.

 

I guess maybe it is just up to a normal level of reservoir, for example 50% level of reservoir?

 

Of course, I am not able to measure the volume of reservoir’s steam coil (it is closed). It seems this volume does not have a much effect on what I measured. I think maybe the volume decreased up to 850 liters.

 

I will be really grateful if you could help me.

 

If you need any other information, I will be glad to present the data.

 

[Erwin APRIANDI]

Hi Meysam_45000,

 

I think I am much more confuse, I'm trying to understand what is you are trying to ask in this thread but I don't seems to find it.

As you know the principle of cooling inside the compressor or pump casing & packing is just same as other cooling system, means it is depend on the flow of the cooling to gain the heat (Remember, Q/hr = m/hr . Cp . dT), so the heat transfer is not related to the volume of the reservoir. However, the cooling medium volume in the system will expand as it will have increase in temperature from it normal filling temperature, that is the possibility why the manual said to fill only up to 600 liters, so there will be and extra volume in the reservoir to acomodate the expansion volume of the cooling medium.

 

Hope this help

[Meysam_45000]

Dear Erwin APRIANDI,

Thank you for your attention.

Actually, our measuring is for adjusting the volume percent of Glycol and Water (20% and 80%). We need to know the total volume of cooling system as well as pipes to understand how much we have to add Glycol for keeping the recommended volume percent.

 

As you know this mixture is vital for preventing from water freezing and also for keeping the suitable fluid heat transfer ( the more glycol volume percent, the more decrease in amount of convection heat transfer coefficient).

 

The big difference between manual (600 liters) and the measuring (900 liters) is not able to satisfied just by the tiny difference in density. As I said this measuring is just for the reservoir, so if I included the volume of heat exchangers, It would be somehow higher than 900 liters.

[Art Montemayor]

I also am confused in trying to understand what it is that you want to find out.  I think you believe you have a complex system in trying to calculate its total volume.  If that is your concern, then the answer is very simple:

1. fill up the entire system will plain water up to the recommended level;
2. drain the entire system water content into buckets or a convenient lower level container;
3. measure or weigh the water contents as they are drained;
4. knowing the total  amount of water content, you can convert this to weight content;
5. knowing the weight content, you fill the system with the % weight of glycol for the system and add the remaining demineralized water to make the recommended level.

 

 

 

 

[Meysam_45000]

Dear Art Montemayor,

Thanks for your answer.

 

As you said the most simple answer is filling the system and then measuring the volume, anybody knows that. You know, we cannot trip the cooling system in two following years (up to overhaul) and also need to adjust the volume percent of Glycol.

 

I am now working on it and if I catch the answer, I will share it. I think I have not been able to share my problem in a clear way.

 

thanks again for your time and attention.

[Meysam_45000]

Dear Friends,

 

Thank you for your attention, finally I found the solution. There is an operating level for cooling reservoir. The recommended filling amount is based on operating level. The total volume of reservoir is different. I found that operating volume of reservoir is exactly 50% of the total volume of reservoir.